The early Visean (Carboniferous) conodonts from the Saoura Valley, Algeria
TAMARA I. NEMYROVSKAl, MARIE-FRANCE PERRET-MIROUSE2 & MARCEL WEYANT3
1 Institute of Geological Sciences of the National Academy of Sciences of Ukraine,o. Gonchar Str., 55-b, 052054 Kiev, Ukraine.
Email: tnemyrov@i.com.ua;tnemyrov@mail.ru
2 Universite Paul Saba tier, Laboratoire de Mecanismes et Transferts en Geologie, Equipe de geodynamique, 14Avenue Edouard Belin, 31400, Toulouse, France.
E-mail: perret@lmtg.obs-mip.fr
3 71 rue Alfred Hare!, Anisy, 14610 THAON, France.
E-mail: marcelweyant@wanadoo.fr
ABSTRACT:
NEMYROVSKA, T.I., PERRET-MIROUSE, M.-F. & WEYANT, M. 2006. The early Visean (Carboniferous) cono- donts from the Saoura Valley, Algeria. Acta Geologica Polonica, S6 (3), 361-370. Warszawa.
The present study reports on conodonts from the El Hariga Formation (lower Visean) of the Saoura Valley, Algeria. This formation overlies the Hassi Sguilma Formation with the latest Tournaisian conodont assemblage with Scaliognathus anchoralis and it is overlain by the Mazzer Formation with the mid-Visean conodont fauna with Gnathodus bilineatus. The conodont assemblage of the El Hariga Formation contains the latest Tournaisian gnathodontids and the Visean Pseudognathodus and unornamented early Visean species of Lochriea. A new species, Lochriea saharae, a probable earliest representative of Lochriea is described. Its relationships to L. cracoviensis, L. commutata and Bispathodus stabilis are discussed.
Keywords: Visean, Carboniferous, Conodonts, Saoura Valley, Algeria, Biostrati- graphy, Taxonomy.
INTRODUCTION
The aim of this paper is to present data on cono- donts from the El Hariga Formation of the Saoura Valley, Algerian Sahara, which was regarded as early Visean in age on the basis of ammonoids (PAREYN 1960-1961; LEMOSQUET & PAREYN 1985;
LEMOSQUET, CONRAD & MANGER 1985). The third author of the present paper was not able to zone the Visean of the Saoura Valley by means of cono- donts at that time (WEYANT 1985) but also sup-
posed the El Hariga Formation to belong to the lower, if not the lowest Visean.
After the first reports on the Carboniferous conodonts of Lys & SERRE (1957) and REMACK- PETITOT (1960), large collections have been made from various areas located north of the Reguibat Shield and the Hoggar, including the Bechar Basin.
The conodont succession of the Bechar Basin, from the Tournaisian through the early Moscovian, is the reference sequence for comparison with the faunas from other Saharan areas (WEYANT 1985). The El
Hariga Formation of the Saoura Valley, which is located to the south of the Bechar Basin, contains abundant and diverse conodont faunas, three levels with ammonoids, and corals and brachiopods in the uppermost beds of the formation.
GEOLOGICAL SETTING AND BIOSTRATI- GRAPHY
The study area is located to the north-west of Beni-Abbes on the west bank of Wadi Saoura,
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which separates the dune-fields of the Grand Erg Occidental in the east from the very flat Hamada du Guir-plateau stretching to the west (Text-fig. 1).
The Visean starts in the Saoura Valley with the EI Hariga Formation, which consists of a rather monotonous sequence of red and greenish shales with very scarce intercalations of thin siltstone and limestone layers. Outcrops are visible over a limit- ed area about 20 km long. The overall strike of the rocks is NW-SE, and the dip ranges from 3 to SO northeast. The thickness of the EI Hariga
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Fig. 1. Location of the investigated area on the simplified geological map of the Saoura Valley, Algeria
Formation according to PAREYN (1961, p. 43) is up to 750 m, but this may be an overestimate.
The conodont samples and the ammonoids were not collected from the same outcrops but from outcrops situated relatively close to one another. The individual limestone beds that were sampled for conodonts are difficult to follow later- ally, the outcrops being frequently interrupted and hidden by constantly wandering alluvial deposits.
For the same reason there will always remain some uncertainty concerning: 1) precise identification of the beds from which ammonoids were collected by PAREYN in the mid-1950s, and 2) whether they can be correlated with any of those which yielded cono- donts two decades later. Therefore the ammonoid occurrences are not shown in Text-fig. 2.
The El Hariga Formation overlies the brown sandstones and quartzites and shales of the Hassi Sguilma Formation, the last thin carbonate layer of which contains the conodonts Scaliognathus anchoralis BRANSON & MEHL and Pseudopoly- gnathus pinnatus VOGES of the latest Tournaisian.
This age was supported by LEMOSQUET & MANGER, who noted that "the Hassi Formation is charac- terised by the appearance of the goniatites Pericyclus and Merocanites along with the climax of Muensteroceras" (LEMOSQUET & al. 1985). From the upper part of the Hassi Formation above the limestone bed with Scaliognathus anchoralis PAREYN (1961) described a diverse Fascipericyclus- Ammonellipsites zonal fauna (PAREYN'S SIb level) which indicates an earliest Visean age (RILEY, per- sonal communication, 2001)
The lower part of the El Hariga Formation was assigned to the earliest Visean Pseudo- gnathodus homopunctatus conodont Zone where- as the upper part was considered as belonging to the Gnathodus bilineatus Zone (WEYANT 1985).
Within the El Hariga Formation PAREYN (1961) distinguished three levels with ammonoids. The lower two levels (S2a and S2b) contain the BeyrichocerasBollandoceras zonal fauna (Meroca- nites, Beyrichoceratoides and Muensteroceras, acme and subsequent disappearance of Mero- canites, extinction of Muensteroceras, presence of Nautellipsites) and are early Visean in age (PAREYN 1961; LEMOSQUET, CONRAD & MANGER 1985; KORN, personal communication, 2000, and RILEY, personal communication, 2001). The third ammonoid assemblage - S2c or the upper part of the El Hariga Formation, is characterised
by the appearance of the earliest representatives of the Goniatites fauna with spiral striae. It con- tains Maxigoniatites saourensis PAREYN (Goniatites maxima saourensis PAREYN 1961) and, according to KORN (personal communication, 2001), is mid-Visean or even earliest late Visean in age.
The El Hariga Formation is overlain by the basal crinoidal limestone beds of the Mazzer Formation with Gnathodus bilineatus (ROUNDY) and late Visean benthic organisms. SEMENOFF- TIAN-CHANSKY & al. (1975) reported the lithostro- tionid corals Siphonodendron gr. martini and S. gr.
pauciradiale sp. A from the top of the El Hariga Formation. LEGRAND-BLAIN (personal communi- cation, 2003) found the spiriferid brachiopod Frechella Jascicostata in the uppermost beds of the formation
CONODONTS
Fourteen conodont samples were taken from the limestone beds of the El Hariga Formation (Text-fig. 2). Each sample was 1 to 1.5 kg. They yielded 916 conodont elements, an average 60-70 elementslkg.
The platform elements outnumber the rami- forms: 537 platform elements and 379 ramiforms were registered.
The conodont faunas from the El Hariga Formation contain well preserved specimens of the genera Gnathodus, Pseudognathodus and Lochriea.
As in the other Carboniferous sequences all over the world, Gnathodus appears in the late Tournaisian in the Saoura Valley, and includes a much larger number of species than Lochriea, and Pseudognathodus, which started in the Visean.
Gnathodus and Lochriea go through the Visean and Serpukhovian and become extinct near the mid- Carboniferous boundary. The range of the Pseudognathodus species is restricted here to the Visean.
The Gnathodus species dominate throughout the succession. Gnathodus semiglaber BISCHOFF, Gn. pseudosemiglaber THOMPSON & FELLOWS and Gn. delicatus BRANSON & MEHL, known from the underlying Hassi Sguilma Formation (late Tournaisian), occur in the El Hariga Formation.
Gn. pseudosemiglaber is most abundant in the El Hariga Formation (108 specimens in 14 samples)
but not as abundant as in the Hassi Sguilma Formation (1439 specimens in 4 samples). It over- laps On. bilineatus in the lowermost part of the overlying Mazzer Formation (Text-fig. 2). On.
semiglaber and Pseudognathodus homopunctatus
(ZIEGLER) are common. Onathodus texanus
ROUNDY was found rather rarely in the lowest limestone beds of the EI Hariga Formation togeth-
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er with M elements of Lochriea and Pa elements of the new species of Lochriea - L. saharae sp. nov.
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(BELKA) and Bi. stabilis and L. saharae sp. nov., as well as Mestognathus beclananni BISCHOFF were also found. Abundant ramiform elements found in the EI
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Lithology
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Hariga Formation and basal beds of the Mazzer Formation are assigned to the multi-element species Kladognathus tenuis!completens (BRANSON & MEHL), emend. REXROAD, Synclydognathus geminus (HIN- DE), Hindeodus cristulus (YOUNGQUIST & MILLER) and Idioprioniodus healdi (ROUNDY).
The upper part of the EI Hariga Formation is characterised by the first appearance of Gnathodus praebilineatus BELKA (rare), Gnathodus girtyi HAss (early subspecies), transitional forms between Gn.
pseudosemiglaber and Gn. girtyi as well as L. com- mutata (BRANSON & MEHL) and L. cracoviensis BELKA. Gn. pseudosemiglaber and L. saharae sp.
nov. are common in the upper part of the EI Hariga Formation. Lochriea species are more abundant in the overlying Mazzer Formation (169 specimens in 5 samples) than in the EI Hariga Formation (79 specimens in 14 samples). This is in contrast to Pseudognathodus homopuctatus (ZIEGLER) and Psg.
symmutatus (RHODES, AUSTIN & DRUCE), which are less common in the Mazzer Formation (32 specimens in 5 samples) than in the EI Hariga Formation (80 specimens in 14 samples). The first rare Gn. bilineatus and Vogelgnathus campbelli (REXROAD) were recorded in the lowest beds of the Mazzer Formation.
The conodont association of the EI Hariga Formation contains a number of simple unorna- mented early Lochriea species with intermediate forms between them as well as between them and their probable ancestor Bi. stabilis. These transi- tional forms between Pa elements of Bi. stabilis and L. commutata were recorded already in other areas (MEISCHNER & NEMYROVSKA, 1999). As we regard the Lochriea lineage to be important for Visean stratigraphy, we have tried in this paper to define the early species of that genus more precisely, pay- ing particular attention to the earliest Lochriea species in the EI Hariga Formation: L. cracoviensis, L. commutata and the new species L. saharae.
Well known and widespread in the Visean and Serpukhovian, conodonts of the genus Lochriea display a great variety in their platform ornamen- tation, ranging from totally unornamented to sculptured ones with nodes or ridges (MEISCHNER, 1970; HIGGINS, 1975; NEMIROVSKAYA & al. 1994;
SKOMPSKI & al. 1995). The morphological trends within the genus Lochriea from unornamented to sculptured forms with rich ornamentation are of stratigraphical importance. One of the first orna- mented Lochriea - L. nodosa BISCHOFF, is a mark-
er-species of the latest Visean conodont zone, and the strongly ornamented species L. ziegleri NEMYROVSKA, PERRET & MEISCHNER (or L. cruci- formis CLARKE) is proposed to serve as marker- species for the identification of the Visean/
Serpukhovian boundary in Eurasia (SKOMPSKI &
al. 1995, NEMYROVSKA 1999, NEMYROVSKA, 2005).
After being widespread through the Visean and Serpukhovian, Lochriea species became extinct together with the other Mississippian conodonts by the mid-Carboniferous boundary.
MEISCHNER (1970) and later HIGGINS (1975), PARK (1983), BELKA (1985) and MEISCHNER &
NEMYROVSKA (1999) cited Bispathodus stabilis as a root stock of Lochriea. L. commutata was men- tioned already by MEISCHNER (1970) as the most conservative species spanning the interval of the Visean and Serpukhovian. During its evolution it gave rise to many species with an ornamented cup (SKOMPSKI & al. 1995). Pa elements of L. commuta- ta as well as of all the succeeding species of Lochriea are characterized by broadly ovate and slightly asymmetrical cups positioned at the poste- rior end of the elements. The denticles of the blade and carina are fused and those of the carina may be widened laterally. The Pa element has an almost rectangular shape in lateral view.
L. cracoviensis is a short-ranged species and its descendants are not known. The cup of its Pa ele- ment is located not at the posterior end of the ele- ment but slightly shifted anteriorly. The laterally widened denticles crown not only its carina but also the posterior part of the free blade.
Bispathodus stabilis (BRANSON & MEHL) , which is morphologically similar to the early sim- ple Lochriea species, also represents a conserva- tive species, first recorded in the late Devonian.
It was subdivided into two morphotypes by ZIEGLER, SANDBERG & AUSTIN (1974). Bi. stabilis Morphotype 2 is regarded as a more advanced form of Bi. stabilis with the basal cavity already shifted posteriorly; it occurs in the Mississippian, and might be an ancestor of Lochriea. Its last occurrence in the Saoura Valley sections is in the Hassi Sguilma Formation underlying the EI Hariga Formation.
In spite of the morphological similarities between the Pa elements of Bi. stabilis Morphotype 2 and L. commutata and the presence of intermedi- ate morphologies, there are essential differences between them:
1. The basal cavity of Loehriea is supposed to be positioned at the posterior end of the element;
only in the earliest forms can the carina extend beyond the cup posteriorly.
2. The basal cavity in Loehriea occupies no more than one third of the element length whereas in Bi. stabilis Morphotype 2, even if the cavity is close to the posterior end (which is very rare), it starts at the middle of the element.
3. The basal cavity is generally subcircular to sub- quadrate in shape and asymmetrical in Loehriea, whereas in Bispathodus stabilis Morphotype 2 it is oval, elongate and mostly symmetrical. There are also specimens of Bi. stabilis with a rather narrow basal cavity.
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4. The blade-carina in Loehriea consists of denti- cles, which become wider laterally and are locat- ed directly on the flaring of the cup. In Bi. stabilis the denticles never tend to be wider laterally and are located on a wider basis below which the flar- ing of the cup starts.
5. Bi. stabilis and Loehriea species can be easily dis- tinguished in lateral view. At the anterior end several discrete denticles of Bi. stabilis are much higher than the others whereas the lateral pro- file of early Visean species of Loehriea is almost rectangular.
Pa elements of L. eraeoviensis are easily distin- guished from those of L. eommutata by their broad carina consisting of laterally expanded den- ticles, and especially by the broad posterior part of the free blade, close to the cup, which also bears laterally expanded denticles. The denticles can be "expanded to form transverse ridges ... , the blade extends beyond the oval-shaped cup at the posterior end" (BELKA 1985). Thus, the differ- ences between the Pa elements of all the Loehriea species and those of L. cracoviensis are evident: a) the cup (basal cavity) of L. eraeoviensis is not positioned at the posterior end of the element as it is in other Loehriea species; and b) in L. eraco- viensis both the carina and the posterior part of the free blade are ridged and strongly expanded.
The second feature also distinguishes L. era- eoviensis from Bi. stabilis, the blade of which bears simple denticles in contrast to older Bispathodus which possess either a ridged blade or a blade with double rows of nodes. However, L. era co- viensis resembles older Bi. stabilis in the expan- sion of its ridges onto the posterior part of the blade. The resemblance of the Pa elements of L.
eraeoviensis and Bi. stabilis was the reason for
BELKA (1985) to consider L. eraeoviensis as being derived from Bi. stabilis.
The availability of forms with intermediate features between the Pa elements of Bi. stabilis and L. eraeoviensis and between those of Bi. sta- bilis and L. saharae seems to support the sugges- tion of the derivation of Loehriea from Bi. stabilis (Text-fig. 3), in spite of the other elements (Pb, M and S) of Loehriea differing from those of Bispathodus. Another possibility would be to speculate about the origin of Loehriea from Protognathodus but there is no evidence on their common multi-element construction.
The forms which portray features transition- al between those of Bi. stabilis and L. commuta- ta were found in the lower limestone interbeds of the EI Hariga Formation, in the lower/middle Visean (?) micritic limestones in the French Pyrenees, in the uppermost part of the lower/mid-Visean of the Rheinisches Schiefer- gebirge in Germany (MEISCHNER & NEMYROV- SKA 1999) and in the Cantabrian Mountains, Palencia, in northern Spain (NEMYROVSKA, 2005). Transitional specimens have also been illustrated from other areas of Europe (see syn- onymy list of L. saharae).
SYSTEMATIC PALAEONTOLOGY
Figured specimens of the Marcel WEYANT col- lection are deposited in the Museum d'Histoire Naturelle de Nantes, France.
Genus Lochriea SCOTI, 1942
TYPE SPECIES: Spathognathodus commutatus BRANSON & MEHL, 1941(Pa element); Lochriea montanaensis SCOTI, 1942 (M element).
Lochriea saharae sp. nov.
(PI. 1, Figs 6, 10-12, 14-15, 17)
1976. Lochriea commutata (BRANSON & MEHL); R.D.
NORBY, pI. 11, fig. 6.
1981. Gnathodus commutatus (BRANSON & MEHL); I.
METCALFE, pI. 7, fig. 6.
1983. Paragnathodus commutatus (BRANSON & MEHL);
S. PARK, pI. 4, fig. 2.
1990a. Lochriea commutata (BRANSON & MEHL); A.
RAMovs, pI. 4, fig. 10.
1990b. Lochriea commutata (BRANSON & MEHL); A.
RAMovs, pI. 1, fig. 7.
1991. Lochriea commutata (BRANSON & MEHL); J.
STONE, PI. 4, Figs. 6, 9.
1999. Bispathodus stabilis (BRANSON & MEHL) transi- tional to Lochriea commutata (BRANSON &
MEHL); D. MEISCHNER & T. NEMYROVSKA, pI. 4, fig. 4.
2002. Lochriea saharae nomen nudum; T. NEMYROVSKA
& al., p. 47.
HOLOTYPE: Specimen S-lO (PI. 1, Fig. 10 a-c).
TYPE LOCALITY: Saoura Valley section, Sahara, Algeria.
TYPE HORIZON: Sample 3191, base of the Mazzer Formation, mid-Visean, base of the Gnathodus bilineatus Zone.
DERIVATION OF NAME: After Sahara, Algeria, where it was found.
DIAGNOSIS: Pa elements of L. saharae are char- acterised by an oval or slightly subcircular unorna- mented cup positioned close to but not at the pos- terior end of the element. The blade-carina bears mostly simple fused denticles. In lateral view Pa ele- ment slightly arched with subrectangular shape common for simple unornamented Lochriea.
MATERIAL: 32 specimens.
DESCRIPTION: The blade-carina is made of mostly simple fused denticles. It extends beyond the platform posteriorly. The denticles of the carina can be slightly expanded laterally like in L. commu- tata. The carina is slightly curved posteriorly (some specimens show a considerable curvature). The smooth, unornamented cup is oval to subcircular, symmetrical to slightly asymmetrical; its outer side is commonly wider. Its anterior margin is close to the mid-point of the element .or is shifted slightly posteriorly, but the posterior margin of the plat- form never reaches the posterior end of the ele- ment. The Pa element is slightly arched in lateral view. Its anterior end is slightly higher. Both anteri- or and posterior ends of the element are subrectan- gular to almost rectangular.
REMARKS: When BRANSON & MEHL (1941) dis- tinguished Spathognathodus commutatus they pointed out that the basal cavity "is close to the posterior end of the blade". Subsequent workers, starting from BISCHOFF (1957), did not concen- trate on this feature. Only HIGGINS (1975), in accordance with BRANSON & MEHL, mentioned the position of the basal cavity close to the poste- rior end, but all of his illustrated specimens actu- ally show the cavity located at the extreme poste- rior end of the blade.
We noticed that the position of the basal cavity
368 NEMYROVSKA of the forms assigned to L. commutata varies from
older rocks to younger ones. The basal cavity seems to have shifted posteriorly during evolution in early Visean time. The shape of Pa elements in lateral view also underwent changes - from slightly arched to subrectangular or rectangular in L. commutata.
The cavity shape became more sub circular. Thus the early L. commutata are closer to Bi. stabilis than the later ones. We did not find L. commutata with the blade-carina extending posteriorly beyond the platform in the upper Visean and Serpukhovian deposits, although some specimens with a very prominent carina posteriorly were found even in the lowest Serpukhovian beds (our unpublished records from the Sahara and other areas). We regard the position of the basal cavity to be a very important diagnostic feature and on this basis we distinguish L. saharae sp. nov. from L. commutata.
Even in juveniles of L. commutata the basal cavity is always located at the posterior end of the element (PI. 1, fig. 7). Lochriea saharae additionally differs from L. commutata in its slightly arched lateral shape.
Lochriea saharae is distinguished from L. cra- coviensis by the simple carina-blade denticles. The latter can be slightly widened on the carina but never on the posterior part of the blade. Lochriea cracoviensis also probably derived from Bi. stabilis but it might belong to another lineage. In the EI Hariga section, its entry occurs a little later than that of L. saharae; in the mid-Arundian of South Wales it was not found at all, but the forms assigned by STONE to L. commutata portray the features of L. saharae (STONE 1991, pI. 4, fig. 6, 9). Both species, L. saharae sp. nov. and L. cracoviensis, are the earliest Lochriea, but additional sections need to be studied in order to understand better the rela- tionships between them.
Lochriea saharae differs from Bi. stabilis in a more subcircular and more asymmetrical and deep- er basal cavity located closer to the posterior end of the unit than that in Bi. stabilis. It also differs from Bi. stabilis in the shape of the blade in lateral view:
in the absence of the much higher discrete denticles at the anterior end of the blade in Bi. stabilis.
RANGE: Lochriea saharae sp. nov. first occurs in the basal beds of the EI Hariga Formation together with the other early Visean conodonts characteris- tic of the strata younger than the Scaliognathus anchoralis Zone. This association consists of abun-
dant Gnathodus pseudosemiglaber, less common Gn. semiglaber, rather rare Gn. texanus, common Pseudognathodus homopunctatus, forms transition- al between Gn. pseudosemiglaber and Gn. girtyi, L.
cracoviensis and the first rare Gn. praebilineatus.
The conodont assemblage is no younger than early Visean in age.
At the base of the Mazzer Formation, L.
saharae sp. nov. is also accompanied by rare Gn.
praebilineatus and Gn. bilineatus, together with more common L. commutata. Because of the entry of Gn. bilineatus s.l., the conodont association belongs to the early late Visean.
Although the exact range of L. saharae cannot be defined from the material available, its approxi- mate range could be estimated as early- through mid-Visean. It has not been found so far in the Upper Visean and Serpukhovian deposits of the Saoura Valley and other areas.
We do not know how exactly to correlate the limestone beds with conodonts in the study area to the three levels with ammonoids of PAREYN. We only know that none of the ammonoid workers who knows the PAREYN collection from the EI Hariga Formation, i.e., Nick RILEY, Walter MANGER and Dieter KORN, regard the EI Hariga as earliest Visean As mentioned above, they consider the lower part of the EI Hariga Formation as early Visean in age and the upper part as early late Visean (see the chapter "Geological setting and biostratigraphy"). This means that we cannot prove (by means of the other fossils) that L. saharae appears in the earliest Visean. However, because this species show intermediate features between those of Bi. stabilis and L. commutata, we believe it is the earliest Lochriea.
Additional studies are required to prove our suggestions. The data from Central Asia (Tien Shan and the Fergana Valley in particular), where the Visean is represented by different types of facies: from carbonate platform through slope to basinal facies, are important. The age of some successions in those areas are controlled by ammonoids. The Chinese and the Urals (Russia) sections might be also important in this respect.
OCCURRENCE: Samples 3175, 3174, 3009, 3011, 3180, 3178, 3191; lower Visean through mid- Visean; Gnathodus praebilineatus Zone through the beginning of the Gn. bilineatus Zone.
Acknowledgements
The authors acknowledge Dr. Marie LEGRAND- BLAIN for information and discussions on the Mississippian benthic fossils in the Sahara sections.
Tamara NEMYROVSKA is grateful to Drs N. RILEY, D.
KORN and W MANGER for helpful information and dis- cussions on the ammonoids of the Saoura Valley sections.
The authors are indebted to Prof. Z. BELKA, the journal referee, for his valuable remarks. This study was made possible by a visiting scientists' grant to the first author, resulting from the Agreement of the cooperation between the University Paul Sabatier, Toulouse, France, and the National Academy of Sciences of Ukraine. IRD and L.M.T.G. (UMR5563-Toulouse) are also thanked for financial support and assistance.
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PLATE 1
la, b, 6, 8, 16 - Bispathodus stabilis (BRANSON & MEHL, 1934) transitional to Lochriea cracoviensis BELKA, 1985; 1a - S-l, oral view, 1b - the same specimen, denticle microsculpture, x 480, sample 1168;
6 - specimen S-6, oral view, sample 3017; 8 - S-8, oral view, sample 3178; 16a-b - S-16, oral view and microsculpture, x 480, sample 3191.
2-3 -Bispathodus stabilis (BRANSON & MEHL, 1934) transitional to Lochriea saharae sp. nov.; 2 - S-2, oral view, x 80, sample 3175;
3 - specimen S-3, oral view, sample 1168.
4 - Lochriea cf. ? saharae sp. nov.; S-4, oral view, sample 3174.
5,9-11,13-14 - Lochriea saharae sp. nov.; 5 - S-5, oral view, juvenile, sample 3009;
9a-b - S-9, oral and lateral view, sample 3178;
10 - S-lO, holotype, a - oral view, b -lateral view, c - microsculpture, x 200, sample 3191;
11 - S-l1, oral view, sample 3191;
13 - S-13, lateral view, sample 3011;
14 - S-14, lateral view, sample 3753.
7,15 - Lochriea commutata (BRANSON & MEHL, 1934) ; 7 - S-7, 15 - S-15;
oral views, sample 3180.
12 - Lochriea saharae sp. nov. transitional to L. commutata (BRANSON
& MEHL, 1934); S-12, oral views, sample 3011.
Magnifification x 60, when otherwise indicated
PLATE 2
1-2 - Lochriea cracoviensis BELKA, 1985; 1 - specimens S-17; a - oral view and b - microsculpture, x 300; 2 - S-18, oral view; both from sample 3180.
3-12,14-15 -Lochriea commutata (BRANSON & MEHL, 1934).
Pa elements: 3 - S-19, lateral view, sample 3180; 4 - S-20, oral view, sample 3017.
Pb elements (can be vicariously shared between L. commutata, L. saharae and L. cracoviensis):
5-7, 14-15 - DE - Subbryanthodus subaequalis HIGGINS, 1961 ; 5, 7 - S-21 and S- 22, sample 3009; 6 - S-23, sample 1168; 14-15 - S-24 and S-25, sam- ple 3191.
M elements (can be vicariously shared between L. commutata, L. saharae and L. cracoviensis):
8-9 - DE - Neoprioniodus singularis (RAss, 1953); 8 - S-26, sample 3175; 9 - S-27, sample 3191.
S elements (can be vicariously shared between L. commutata, L. cra- coviensis and L.saharae):
Sa element:
10 - DE - Hibbardella pennata Higgins, 1961, S-I21, sample 3191.
Sb elements:
11-12 - DE - Hindeodella germana HOLMES, 1928; 11 - S-28, sample 3191;
12 - S-29, sample 3011.
13 - Ozarkodina sp. 1; 13 - S-30, sample 3011.
16, 19-20 - Ozarkodina sp. 2; 16 - S-31, sample 3017 (? Subbryanthodus stipans REXROAD, 1957); 19 - S-32, sample 3009; 20 - S-33, sample 3191.
17 - Pseudognathodus symmutatus (RHODES, AUSTIN & DRUCE, 1969);
17 - S-34, oral view, sample 3009.
18 - Ozarkodina hindei CLARKE, 1960; 18 - S-35, sample 3009.
Magnification x 60, when otherwise indicated
PLATE 3
1- Gnathodus texanus ROUNDY, 1926; S-36, sample 3174.
2-8,10,14 - Gnathodus pseudosemiglaber THOMPSON & FELLOWS, 1970; 2, 6 and 7 -S- 37, S-38 and S-39, sample 3175; 3 - SAO sample 3009; 4 - SAl, sample 3111; 5 - S-42, sample 3191; 8 - S-43, sample 1168;
10 - SA4, sample 3180; 14 - SA5, sample 3180.
9,11,18 - Gnathodus pseudosemiglaber THOMPSON & FELLOWS, 1970, transi- tional to Gn. girtyi s.l. HAss, 1953; 9 - S-46, sample 3009; 11 - S-47, sample 3011; 18 - S-48, sample 3180.
12, 16 - Gnathodus semiglaber BISCHOFF, 1957; 12 - S-49, sample 3175; 16- S-50, sample 1168.
13, 15, 17, 19 - Gnathodus girtyi aff. intennedius GLOBENSKY, 1967; 13 - S-51 sam- ple 3011; 15 - S-52 sample 3009; 17, 19 - S-53 and S-54, sample 3191.
Magnification x 60
PLATE 4
1-5, 7 - Pseudognathodus homopunctatus (ZIEGLER, 1960); 1 - S- 55, sample 3011; 2, 7a, b - S- 56 and S- 57, a) oral view, b) microsculpture, x 400, sample 3191; 3, 5 - S-58 and S-59, sample 3180; 4 - S-60, sample 3009.
6, 9, 11-13, 15, 20, 22 - Gnathodus praebilineatus BELKA, 1985; 6 - S-61, sample 3011, specimen showing trend from Gn. delicatus BRANSON
& MEHL, 1938; 11, 15, 22 - S-62, S-63 and S-64, sample
3009; 12, 20 - S-65 and S-66, sample 1168, specimen S-66 showing trend from Gn. semiglaber BISCHOFF, 1957; 9, 13 - S-67 and S-68, sample 3191, specimens showing trend from Gn. semiglaber BISCHOFF, 1957.
8 - Gnathodus joseramoni SANz-LoPEZ, BLANCO-FERRERA &
GARCIA-LoPEZ,2004; S-69, sample 3009.
10,14,17- Gnathodus delicatus BRANSON & MEHL, 1938, transitional to Gn. praebilineatus BELKA, 1985; 10, 17 - S-70 and S-71, sample 3011; 14 -
s-n,
sample 319l.16 - Mestognathus ?beckmani BISCHOFF, 1957; S-73, sample 3753;
18 - Gnathodus sp.; 18 -- S-77, sample 3174, specimen showing trend from Gn. semiglaber BISCHOFF, 1957.
19 - Gnathodus aft. girtyi meischneri AUSTIN & HUSRI, 1974;
S-78, sample 3188.
21- Gnathodus semiglaber BISCHOFF, 1957; S-79, sample 3180.
23-25 - Mestognathus beckmani BISCHOFF, 1957; 23, 24 and 25- S-74, S-75 and S-76, sample 3188.
Magnification x 60, when otherwise indicated
PLATES
1-11,14 -Kladognathus tenuis/completens (BRANSON & MEHL, 1941), emend.
REXROAD, 1981.
Pa /Pb elements:
1, 3 - DE Magnilaterella cuntraria RHODES, AUSTIN & DRUCE, 1969, spec- imen S-80, sample 3175 and specimen S-81, sample 3191; 2 - DE Magnilaterella robusta REXROAD & COLLINSON, 1963, specimen S- 82, sample 3011; 4 - DE Magnilaterella clarkei RHODES, AUSTIN &
DRUCE, 1969, specimen S-83, sample 3009.
M elements:
8, 11, 14 - DE Neoprioniodus scitulus (BRANSON & MEHL, 1940); 8 and 14 - S- 84 and S-85, sample 3009,11: specimen S-86, sample 3174.
Sa elements:
5 - DE Hibbardella ortha REXROAD, 1958, specimen S-87, sample 3753, x60;
6 - DE Hibbardella milleri REXROAD, 1958, specimen S-88, sample 1168.
Sc elements:
9 - DELigonodina tenuis BRANSON & MEHL, 1941, specimen S-89, sam- ple 3191; 7,
10 - DE Ligonodina levis BRANSON & MERL, 1941,7 - S-90, sample 3009, and 10 - S-91, sample 1168.
16-25 - Idioprioniodus healdi (ROUNDY, 1926) Pb elements:
17 - DE Metalonchodina bidentata (GUNNELL, 1931), specimen S-92, sample 1168;
12, 15, 19,20 - DE Lonchodina fumishi REXROAD, 1958; 12, 19 - S-93 and S-94, sample 3009; 15 - S-95, sample 3191; 20 - S-96, sample 1168.
M elements:
13 - DE Neoprioniodus conjunctus (GUNNELL, 1931), S-97, sample 3009.
Sa elements:
18 - DE Roundya bamettana RAss, 1953, S-98, sample 3191.
Sc elements:
17 - DE Ligonodina roundyi (RAss, 1953), S-99, sample 3009.
21 - Subbryanthodus sp.; S-100, sample 3011.
Magnification x 50
ACTA GEOLOGICA POLONICA, VOL. TAMARA NEMYROVSKA al., PL.
PLATE 6
1-3,5 -Hindeodus eristulus (YOUNGQUIST & MILLER, 1949) Pa elements:
1, 2 - DE Hindeodus eristulus (YOUNGQUIST & MILLER, 1949), 1- S-101, sample 3011 and 2 - S-102, sample 3009.
M elements:
3, 5 - DE Neoprioniodus dentieamurus REXROAD, 1957, 3 - S-I03, sample 3011 and 5 - S-104, sample 3017.
4, 8-11 - Synclydognathus geminus (HINDE, 1900) Pa elements:
8 - DE Hindeodus scitulus (HINDE, 1900), specimen S-105, sample 3175, x 60.
Pb elements:
4 - DE Ozarkodina cf. laevipostiea REXROAD & COLLINSON, 1963; S-106, sam- ple 3017.
M elements:
9,10 - DEApatognathus ? sealena VARKER, 1967; 9 - S-107 and 10 - S-108, sam- ple3174;
11- DE Apatognathus ? petila VARKER, 1967, specimen S-109, sample 3175.
7,13 -Idioprioniodus eonjunetus (GUNNELL, 1931) S elements:
7, 13 - DE Hindeodella ibergensis BISCHOFF, 1957, 7 - S-110, sample 3009 and 13 -S-111, sample 3011.
6 - Hindeodella sp.; S-112, sample 3011.
12 - Hindeodella uneata (BAss, 1959); S-113, sample 3009.
14 - Ligonodina fragilis BAss, 1952; S-114, sample 3009.
15-16 - Hindeodella hibbardi COLLINSON & DRUCE, in RHODES, AUSTIN & DRUCE, 1969; 15 - S-115, sample 3017; 16 - S-116, sample 3009.
17-18 - Ozarkodina roundyi BAss, 1952; 17 - S-117, 18 - S-118, sample 3011.
19 - Hindeodella eorpulenta BRANSON & MEHL, 1934; S-119, sample 3009 20 - Synprioniodina mierodenta ELLISON, 1941; S-120, M element of Gnathodus
sp., sample 3175.
21 - Undetermined element; S-122, sample 3009.
22 - Lonehodina projeeta (ULRICH & BASSLER, 1926); S-123, sample 3191.
23 -Lonehodina sp.; S-124, sample 3009.
Magnification x 50, when otherwise indicated
